1. Technical Field
The present disclosure relates to a display device and, more particularly, to a display device for generating sound by vibrating a display panel and a sound-generating actuator fixing structure used therefore.
2. Discussion of the Related Art
With the development of various portable electronic devices, such as a mobile communication terminal and a notebook computer, a desire for a flat panel display device applicable thereto is increasing. The flat panel display devices include a liquid crystal display (LCD) device, an electroluminescence display device, a light-emitting diode (LED) display device, and an organic light-emitting diode (OLED) display device.
Among these display devices, the liquid crystal display (LCD) device includes an array substrate including an array of thin film transistors, an upper substrate including a color filter and/or a black matrix, etc., and a liquid crystal material layer formed therebetween. An alignment state of the liquid crystal is controlled according to an electric field applied between two electrodes of a pixel area, and thereby, the transmittance of light is adjusted to display images.
Recently, an organic light-emitting diode (OLED) display device coming into the spotlight as a display device has advantages of a fast response time, high light-emitting efficiency, high luminance, and a wide viewing angle by using an OLED that emits light by itself, i.e., is “self-emitting.”
Meanwhile, a set device or a finished product including such a display device as described above may include, for example, a television (TV), a computer monitor, or an advertising panel. Such a display device or set device may include a sound output device, such as a speaker, for generating and outputting sound relating to a displayed image.
Typically, a company that manufactures a display portion of a device, such as a liquid crystal display device or an organic light-emitting diode display device, manufactures only a display panel or a display device, while another company that manufactures a speaker assembles the speaker with the manufactured display portion, to complete a set device capable of outputting images and sound. The reverse assembly may also be done, but still in two parts and often in different manufacturing facilities.
FIG. 1 is a plan view of a speaker included in a related art display device.
As shown in FIG. 1, the related art display device 1 or a set device includes a speaker 2 disposed on a rear part or a lower part of a display panel thereof. In this structure, the sound generated by the speaker 2 does not progress directly toward a viewer, who is viewing an image from the front side of the display device 1, but progresses toward the rear part, the lower part, or the edge of the display panel, rather than the front part of the display panel on which the image is being displayed. Therefore, the sound's mismatched directionality may disturb the viewer's immersion experience. In addition, when the sound generated from the speaker 2 progresses toward the rear part, the lower part, or the edge of the display panel of the display panel, the sound quality may be degraded due to an interference with sound reflected by walls, floors, or other surfaces at the rear of or below the display panel.
In addition, the sound generated by a speaker included in the related art display device is not oriented toward a viewer of the display device, and may thus undergo diffraction, which further degrades the sound localization. Moreover, in configuring a set device, such as a TV, a speaker may occupy an undesirably large amount of space, which imposes a restriction on the design and spatial disposition of the set device. In mobile devices, for example, the speaker takes up space that forces a larger size in thickness and/or bezel area.
On the other hand, a technology in which a display panel or a diaphragm attached to a display panel is vibrated by an actuator to output sound, has recently been proposed. Such a sound output scheme may include a diaphragm for generating sound in addition to a display panel, and a scheme of fixing a sound-generating actuator to a support structure of the display device is complicated. Therefore, it is necessary to develop a structure for fixing, to a display device, an actuator for generating sound by vibrating a display panel or a diaphragm.